1. Field of the Invention
The present invention is related to a flash memory device with shunt, and more particularly to a flash memory device with shunt comprising a switch set up as short through a shunt activation signal of an external transmission interface such that when the flash memory controller incur errors or damages, the shunt enables access directly from the external control terminal to the flash memory chip through the external transmission interface for processing saving/retrieving data or testing.
2. Description of Related Art
Nowadays, the technology of the flash memory is being rapidly developed, and the manufacturers have progressively created the flash memory with larger capacity, for example, MP3 player, personal digital assistant (PDA), digital camera, digital video camera or other multimedia device. The communication device such as cellular phone has a memory card. The flash memory has different specifications or requests for its application, and different types, sizes and specifications of the memory cards are needed. The available memory cards are mostly MMC (multimedia card), CF (compact flash card), SMC (smart media card), MS (memory stick) and SD (secure digital memory card). The convenience of using the flash memory has made the flash memory an indispensable device.
The types of the flash memories are classified according to their technical structure such as NOR type, NAND type, DINOR type and AND type. The NOR type flash memory has the program code as the main storage and is known as NOR; the NAND type flash memory has the information as the main storage and is known as NAND.
The NAND type flash memory has become the mainstream storage media due to its large capacity and fast processing speed. However, the process of saving and retrieving information and management thereof are very complicated. Therefore, the NAND flash controller is available for simplifying the use of the NAND type flash memory. The NAND flash controller and the NAND type flash memory can be packaged into a single chip to form a multi chip package (MCP). Even though the flash memory interface of the single chip is as the same as the other NAND type flash memory, but the operation procedure thereof is the same as of the conventional ATA device where only the logic address of the flash memory is defined and required no complicated management of the flash memory. But the chip produced in the MCP has problems of testing during the mass production. Because the NAND type flash memory is not directly connected to the lead of the chip, therefore the chip cannot be externally directly be tested or measured.
Furthermore, the conventional MCP may differentiate a packaged chip from the defective chip and when the connection interface between the chips is damaged or defective, the cause of defect carried by the packaged flash memory cannot be located easily in the conventional MCP. Therefore, how to overcome the defect of the conventional design is an important issue for the manufacturer in the field.